Objectives: Licensure of acellular pertussis vaccines awaits the evaluation of several recently completed and ongoing efficacy trials. Results of these trials are dependent upon the laboratory procedures employed to diagnose Bordetella pertussis infection. Similarly, long-term surveillance of the pertussis immunization program requires the development and implementation of sensitive and specific diagnostic procedures. Licensure of less reactogenic acellular pertussis vaccines will provide an opportunity to immunize older age groups, however, data on pertussis morbidity in adults and the role of adults and adolescents in transmission are needed to make appropriate decisions on expanded use of these vaccines. To increase knowledge of pertussis diagnosis and epidemiology, the Laboratory has initiated projects: a) To develop and improve laboratory procedures to diagnose infection with Bordetella pertussis. b) To determine which diagnostic procedures have the highest sensitivity and specificity for pertussis diagnosis at the different stages of illness and ages of patients. c) To apply these techniques to understand epidemiology of pertussis. FY97 Activities: 1. Completed analyses of a collaborative study with US Navy to determine the prevalence of B. pertussis infection in Marine trainees. Infection was evaluated by culture, serology and by polymerase chain reaction (PCR) technology. Previoulsy, the Laboratory of Pertussis performed ELISA tests on serum samples and PCR evaluation on nasopharyngeal samples. No subjects were positive by culture or PCR, however, depending on definition, 1 to 17% of subjects met a serological case definition for pertussis. A manuscript has been accepted for pubication.2. In a follow-up study, antibodies were measured on paired serum samples collected at the beginning and at the end of training from a randomly selected set of 140 trainees from teh same installations as evaluated above. Additionally, a health-status questionnaire was completed at the conclusion of training. Antibodies are being measured to determine normal pre-training antibody levels and the frequency of pertussis-antibody rises in this population.3. Assisted in writing an RFP and one member of the Section served on the technical evaluation panel for CDC contract solicitation entitled "Measurement of antibodies to three antigens of Bordetella pertussis". The goal of the study was to develop serodiagnostic assays that could be transferred to state and regional clinical laboratories.